Continuous casting and rolling apparatus and continuous casting and rolling method

ABSTRACT

A continuous casting and rolling apparatus includes: a continuous casting device; a cutting device that is disposed at the output side of the continuous casting device and cuts an inner slab produced from the continuous casting device; a rolling device pressing down on the slab and disposed downstream of the continuous casting device in the moving direction of the inner slab; a tunnel furnace which is disposed between the cutting device and the rolling device and heats the slab disposed on the main path of the inner slab that is transferred from the continuous casting device to the rolling device; and a loading adjustment unit which is disposed adjacent to the tunnel furnace and unloads the slab from the main path from the outlet side of the tunnel furnace and loads the slab onto the main path from the inlet side of the tunnel furnace.

TECHNICAL FIELD

The present invention relates to a continuous casting and rollingapparatus and a continuous casting and rolling method.

BACKGROUND ART

In a mini mill process, a layout is configured to directly roll a cutslab produced through a continuous casting process without cooling.

A tunnel furnace is installed as a space functioning as a buffer betweena continuous casting device and a rolling device.

This tunnel furnace serves as a space for connecting two continuouscasting devices and a single rolling device and as a buffer space when acertain amount of time is required for rolling mill replacement. Inorder to compensate for a temperature drop while a slab remains in thespace, a heater having a gas heating method or an inducted heatingmethod is installed to compensate for the temperature drop.

In the mini mill process, however, the slab produced in the continuouscasting device is promptly transferred to the rolling device to berolled, thereby causing a problem that an actual yield is significantlyreduced because the slab in the tunnel furnace and that newly producedin the continuous casting device are scrapped when an abnormal operationof the rolling device occurs for a long period of time. That is, theconventional mini mill process is advantageous in terms of energy inthat it employs the continuous casting device and the rolling devicedirectly connected to each other according to a flow of a material butis disadvantageous in that its ability to cope with abnormal operationsis inferior.

Further, an exterior material of a vehicle or a product required to meetstringent surface quality requirements is subject to a scarfing processafter produced using a cut slab, which removes a surface defectgenerated during the continuous casting. To apply the scarfing to themini mill process, however, a scarfing device needs to be installedonline in consideration of the characteristics of the mini mill process,that is, the slab produced in the continuous casting device is promptlytransferred to the rolling device. In this case, it may bedisadvantageous in that the slabs, not subject to scarfing but in aregion in which a scarfing device is installed, are cooled when scarfingis performed for selective slabs.

In addition, there may be a problem that the continuous casting devicemay not operate in the mini mill process, or rolling capacity of therolling device may be wasted according to a slab production speed of thecontinuous casting device.

Accordingly, research into a continuous casting and rolling apparatusand a continuous casting and rolling method is required to solve theabove issues.

DISCLOSURE Technical Problem

An object of the present disclosure is to provide a continuous castingand rolling apparatus for preventing a problem of a reduced actual yieldof a slab while compensating for a temperature drop of the slab duringan abnormal operation, and a continuous casting and rolling method.

Another object of the present invention is to provide a continuouscasting and rolling apparatus for scarfing a slab during the continuouscasting or preventing a problem of wasted capacity of a rolling device,and a continuous casting and rolling method.

Technical Solution

According to an aspect of the present disclosure, a continuous castingand rolling apparatus may include a continuous casting device; a cuttingdevice disposed on an outlet side of the continuous casting device andcutting an inner slab produced in the continuous casting device; arolling device pressing a slab down and disposed downstream of thecontinuous casting device in a moving direction of the inner slab; atunnel furnace provided between the cutting device and the rollingdevice and heating a slab located on a main path of the inner slabtransferred from the continuous casting device to the rolling device;and a loading adjustment unit provided adjacent to the tunnel furnace,separating the slab on the main path from the tunnel furnace andintroducing the slab onto the main path from an inlet side of the tunnelfurnace.

The loading adjustment unit may include a drawing device providedadjacent to an outlet side of the tunnel furnace and separating the slabfrom the main path to be introduced onto a supplementary path; and anintroducing device provided adjacent to the inlet side of the tunnelfurnace and receiving the slab through the supplementary path to beintroduced onto the main path

Further, the loading adjustment unit may introduce the inner slab,separated from the main path of the outlet side of the tunnel furnace bythe drawing device, onto a main path of the inlet side of the tunnelfurnace by the introducing device.

The continuous casting and rolling apparatus may further include areheating device on the supplementary path between the introducingdevice and the drawing device and heating the slab on the supplementarypath.

The continuous casting and rolling apparatus may further include ascarfing device provided on the supplementary path between theintroducing device and the drawing device and heating the slab on thesupplementary path.

The introducing device may receive at least one of an inner slabproduced in the continuous casting device and an outer slab transferredfrom the outside and introduce the same onto the main path.

A continuous casting and rolling method may include a process ofsupplying an inner slab, involving cutting an inner slab produced in acontinuous casting device and supplying the same to a tunnel furnace; arolling process involving pressing down the slab received from a mainpath of the slab moving through the tunnel furnace; and a subworkingprocess performed between the process of supplying an inner slab and therolling process and involving separating the slab on the main path froman outlet side of the tunnel furnace when the rolling process stops andintroducing the slab onto the main path from an inlet side of the tunnelfurnace when the rolling process resumes.

The subworking process may include a drawing process involvingseparating the slab on the main path from the outlet side of the tunnelfurnace when the rolling process stops; and an introducing processinvolving receiving the slab separated from the main path of the outletside of the tunnel furnace and introducing the same onto the main pathof the inlet side of the tunnel furnace when the rolling processresumes.

The subworking process may include the introducing process subsequent tothe drawing process so as to exclude intervention of another processtherebetween, when the slab introduced onto the main path maintains atemperature for rolling.

The subworking process may further include a reheating process performedbefore the introducing process and involving heating the slab introducedonto the main path during the subworking process on the supplementarypath when the slab has a temperature below the temperature for rolling.

The subworking process may further include a scarfing process performedbefore the introducing process and involving scarfing the slab separatedfrom the main path of the outlet side of the tunnel furnace on thesupplementary path through which the slab is delivered to be introducedonto the main path of the inlet side of the tunnel furnace.

The subworking process may further include a process of supplying anouter slab, performed before the introducing process and involvingintroducing the outer slab produced outside onto the supplementary paththrough which the slab separated from the main path of the outlet sideof the tunnel furnace is delivered to be introduced onto the main pathof the inlet side of the tunnel furnace.

The outer slab supply may be performed when capacity of the slabperforming pressing down during the rolling process is larger than asupply amount of the inner slab.

Advantageous Effects

The continuous casting and rolling apparatus and the continuous castingand rolling method of the present invention are advantageous in that aproblem of a reduced actual yield of a slab can be prevented while atemperature drop of the slab can be compensated during an abnormaloperation.

In another aspect, the continuous casting and rolling apparatus and thecontinuous casting and rolling method are advantageous in that scarfingcan be performed for a slab during the continuous casting or a problemof wasted capacity of a rolling device can be prevented.

DESCRIPTION OF DRAWINGS

FIG. 1 is a layout diagram illustrating a moving path of a slab in thecontinuous casting and rolling apparatus of the present invention duringan abnormal operation.

FIG. 2 is a layout diagram illustrating a moving path of a slabcompensating for a temperature loss in the continuous casting androlling apparatus during an abnormal operation.

FIG. 3 is a layout diagram illustrating a moving path for scarfing of aslab in the continuous casting and rolling apparatus.

FIG. 4 is a layout diagram illustrating a moving path for receiving anouter slab in the continuous casting and rolling apparatus.

FIG. 5 is a layout diagram illustrating a moving path for receiving anouter slab and performing scarfing in the continuous casting and rollingapparatus.

FIG. 6 is a diagram illustrating an order of the continuous casting androlling method of the present invention.

FIG. 7 is a diagram illustrating a subworking process during thecontinuous casting and rolling method.

BEST MODE FOR INVENTION

Hereinafter, exemplary embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.Meanwhile, the spirit of the present invention is not limited to thesuggested embodiments, and those skilled in the art to which the presentinvention pertains could easily suggest another embodiment which fallswithin the spirit of the present invention through the addition,modification, and deletion of another component without departing fromthe spirit of the present invention.

In the following description, components having the same function withinthe same scope illustrated in the drawings of the embodiments areillustrated by using the same reference numerals.

The present invention relates to a continuous casting and rollingapparatus and a continuous casting and rolling method. In the presentinvention, a problem of a reduced actual yield of a slab can beprevented, and scarfing can be performed on a slab during the continuouscasting. A problem of wasted capacity of a rolling device 30 can beprevented.

Specifically, with reference to the accompanying drawings, FIG. 1 is alayout diagram illustrating a moving path of a slab in the continuouscasting and rolling apparatus of the present invention during anabnormal operation. Based on FIG. 1, a continuous casting and rollingapparatus according to an exemplary embodiment may include a continuouscasting device 10; a cutting device 20 disposed on an outlet side of thecontinuous casting device 10 and cutting an inner slab IS produced inthe continuous casting device 10; a rolling device 30 pressing a slabdown and disposed downstream of the continuous casting device 10 in amoving direction of the inner slab IS; a tunnel furnace 40 providedbetween the cutting device 20 and the rolling device 30 and heating aslab located on a main path MP of the inner slab IS transferred from thecontinuous casting device 10 to the rolling device 30; and a loadingadjustment unit 50 provided adjacent to the tunnel furnace 40,separating the slab on the main path MP from the tunnel furnace 40 andintroducing the slab onto the main path MP from an inlet side of thetunnel furnace 40.

According to such configuration, the problem of a reduced actual yield,which may be caused by a defect of the rolling device 30 or a scrappedslab during an abnormal operation in which a rolling operation such as areplacement of a transfer roll is impractical, may be prevented.

In other words, the slab located in the tunnel furnace 40 or thatproduced by molten steel remaining in the continuous casting device 10is separated from a main path MP of an outlet side of the tunnel furnace40 by the loading adjustment unit 50 during the abnormal operation andintroduced onto a supplementary path SP. The slab on the supplementarypath SP is reintroduced onto the main path MP of an inlet side of thetunnel furnace 40, thereby increasing a time for which the slab ispositioned on a moving path.

By securing a bypass, on which the slab remains without entering therolling device 30, the slab can be prevented from being wasted by thescrap treatment due to insecurity of the path on which the slab remains.

Besides, the loading adjustment unit 50 introduces the slab introducedonto the main path MP onto an inlet side of the tunnel furnace 40,thereby compensating for a temperature of the slab lowered during itstransfer through the supplementary path SP by a temperature at which therolling can be performed.

The continuous casting device 10 may serve to produce an inner slab ISfrom the molten steel through a casting process. That is, the continuouscasting device 10 supplies the molten steel to a mold in a tundish, andthe supplied molten steel forms a cast while depriving heat. The innerslab IS is guided by a segment roll and a pinch roll and may be movedand supplied to the rolling device 30 to be described later.

Such continuous casting device 10, however, produces the internal caststeel IS depending on a solidification speed of the molten steel, it isdifficult to control a production speed. Accordingly, production of aproduct by continuously receiving the inner slabs IS produced in thecontinuous casting device 10 and pressing down the same using therolling device 30 has a limitation of a speed.

However, the inner slab released from the continuous casting device 10has a high average temperature, it is advantageous in that a temperaturerequired during the rolling operation can be guaranteed.

The cutting device 20 can serve to control whether a slab (inner slab ISor outer slab OS) performing the rolling in the rolling device 30 isprovided as in a continuous form of being connected to the continuouscasting device 10 or in a discontinuous form of being separated from thecontinuous casting device 10. To this end, the cutting device 20 isprovided on an outlet side of the continuous casting device 10.

That is, when the cutting device 20 and allows the inner slab IS tofreely pass without cutting the same, the rolling device 30 receives theinner slab IS produced in the continuous casting device 10 in thecontinuous form of being connected to the continuous casting device 10to perform the rolling. When the cutting device 20 cuts the inner slabIS and transfers the same to the rolling device 30, the rolling device30 receives the inner slab IS in the discontinuous form of beingseparated from the continuous casting device 10 to perform the rolling.

When the rolling device 30 stops due to an abnormal operation, the innerslab IS needs to be introduced onto the supplementary path SP. In thisregard, the cutting device 20 cuts the slab.

The rolling device 30 receives a slab, such as the inner slab ISproduced in the continuous casting device 10 or an outer slab OSprovided from outside, and presses the same to produce a natural orafter product.

To this end, the rolling device 30 can allow the slab to go through apair of rolling rolls to roll the slab, and several rolling standsproviding such a pair of the rolling rolls may be provided.

As described above, the rolling device 30 can roll the slab whilesetting various rolling thicknesses.

The rolling device 30 may be provided as a rough rolling device 30 and afinish rolling device 30. The rough rolling device 30 has aconfiguration in which a slab produced in the continuous casting device10 is first rolled, whereas the finish rolling device 30 has aconfiguration in which the slab rolled in the rough rolling device 30 isfinish-rolled.

When the rolling thickness for the slab is satisfied by the roughrolling device 30, the finish rolling device 30 does not perform therolling but may allow pairs of the rolling rolls to freepass the slab.Alternatively, when the rolling thickness for the slab is formed only bythe operation of the finish rolling device 30, the rough rolling device30 does not perform the rolling but may allow the pairs of the rollingrolls to freepass the slab.

A heater for adjusting a rolling temperature of the slab or ascale-remover removing a scale may be provided on the inlet side of therough rolling device 30 or the finish rolling device 30.

The tunnel furnace 40 serves to maintain or increase a rollingtemperature of the slab when transferring the slab to the rolling device30 and rolling.

To this end, the tunnel furnace 40 is provided between the continuouscasting device 10 and the rolling device 30 and heats the slab, such asthe inner slab IS produced in the continuous casting device 10 or anouter slab OS provided from outside, to maintain or increase the rollingtemperature of the slab.

In another aspect, as a cooling speed can be adjusted as the temperatureof the slab increases or a heating amount decreases, a material of theslab can also be adjusted.

To this end, the tunnel furnace 40 may be provided with a heating meanssuch as a gas heating method, an induced heating method, or the like,and the tunnel furnaces 40 may be provided in plural according to alength thereof.

In particular, the slab is separated to the supplementary path SP fromthe main path MP of the inner slab IS delivered to the rolling device 30from the continuous casting device 10 the tunnel furnace 40 on theoutlet side of the tunnel furnace 40. In the meantime, the loadingadjustment unit 50 introducing the slab from the supplementary path SPonto the main path MP may be connected to the inlet side of the tunnelfurnace 40.

The loading adjustment unit 50 serves to separate a slab from the mainpath MP to be introduced onto the supplementary path SP on the outletside of the tunnel furnace 40 while separating the slab from thesupplementary path SP onto the main path MP on the inlet side of thetunnel furnace 40. This is to prevent the problems that the slab isscrapped and the actual yield thereof is lowered in presence of a defectof the rolling device 30 or a scrapped slab during an abnormal operationin which a rolling operation such as a replacement of a transfer roll,by expanding the path on which the slab remains to the supplementarypath SP. This enables the slab to remain on the main path MP and thesupplementary path SP without being abandoned until the operation isback to normalize.

To this end, the loading adjustment device may include a drawing device51 and an introducing device 52. That is, the loading adjustment unit 50of the continuous casting device according to an exemplary embodiment ofthe present invention is provided adjacent to the outlet side of thetunnel furnace 40 and to the inlet side of the tunnel furnace 40 and thedrawing device 51 separating the slab from the main path MP to beintroduced onto the supplementary path SP. The loading adjustment unit50 may include the introducing device 52 receiving the slab through thesupplementary path SP to be introduced onto the main path MP.

The drawing device 51, located on the outlet side of the tunnel furnace40, serves to deliver the slab from the main path MP to thesupplementary path SP. Accordingly, the moving path of the slab isexpanded by changing the moving path of the slab toward the rollingdevice 30 from the outlet side of the tunnel furnace 40 to thesupplementary path SP.

Such drawing device 51 may include a pusher pushing the slab on thetransfer roll, but is not limited thereto. Any drawing device 51 can beused in the present invention as long as the slab can be delivered fromthe main path MP to the supplementary path SP.

The introducing device 52, located on the inlet side of the tunnelfurnace 40, serves to deliver the slab from the supplementary path SP tothe main path MP. Accordingly, the slab separated from the outlet sideof the tunnel furnace 40 can be delivered toward the rolling device 30.

Further, as being provided on the inlet side of the tunnel furnace 40,the introducing device 52 enables the slab to be heated, therebyincreasing the temperature of the slab, which has lowered while beingtransferred to the supplementary path SP, to a temperature at which theslab can be rolled.

Similarly to the drawing device, the introducing device 52 may include apusher pushing the slab on the transfer roll, but is not limitedthereto. Any introducing device 52 can be used in the present inventionas long as the slab can be delivered from the supplementary path SP tothe main path MP.

The loading adjustment unit 50 of the continuous casting deviceaccording to an exemplary embodiment may serve to introduce the innerslab IS separated from the main path MP of the outlet side of the tunnelfurnace 40 by the drawing device 51 onto the main path MP of the inletside of the tunnel furnace 40 by the introducing device 52.

That is, an additional configuration is not suggested for the movingpath of the slab transferred from the drawing device 51 to theintroducing device 52, and the slab can be configured to transfer whileforming the supplementary path SP directly connecting the introducingdevice 52 to the drawing device 51.

When the supplementary path SP is formed as the above, a length thereofmay be reduced depending on a number of the slabs to remain.

The length of the supplementary path SP is defined in consideration ofan amount of the slab cooled on the supplementary path SP. That is, thetemperature of the slab on the inlet side of the rolling device 30 inconsideration of the amount of the cooled slab reduced on thesupplementary path SP and a degree of a temperature increase in thetunnel furnace 40 added to the slab needs to be higher than atemperature at which the rolling is feasible. In such relationship, amaximum distance of the supplementary path SP is defined.

FIG. 2 is a layout diagram illustrating a moving path of a slabcompensating for a temperature loss in the continuous casting androlling apparatus during an abnormal operation. Based thereon, thecontinuous casting device according to an exemplary embodiment isprovided on the supplementary path SP between the drawing device 51 andthe introducing device 52 and may include a reheater 60 heating the slabon the supplementary path SP.

The reheater 60 is further provided on the supplementary path SP asdescribed above because the range for compensating for the temperaturedrop (cooling amount) of the remained slab on the path in the tunnelfurnace 40 is exceeded according to an increasing amount of the slab,which needs to remain on the supplementary path SP.

This is the case in which the inner slab IS produced in the continuouscasting device 10 is prevented from being disposed and an amount of theinner slab IS remaining on the main path MP or the supplementary path SPincreases in the case of prolonged period of the abnormal operation.

Such reheater 60 may be configured as the tunnel furnace 40. That is,the reheater 60 may be provided with a heating means such as a gasheating method, an induced heating method, or the like, and may beprovided in plural according to a length of a section which is heated.

FIG. 3 is a layout diagram illustrating a moving path for scarfing of aslab in the continuous casting and rolling apparatus. Based thereon, thecontinuous casting device according to an exemplary embodiment mayinclude a scarfing device 70 provided between the introducing device 52and the drawing device 51 on the supplementary path SP and scarfing theslab on the supplementary path SP.

The scarfing device 70 serves to scarf the inner slab IS or the outerslab OS according to a need of a product to be produced.

As an example, as the scarfing device 70 is provided on thesupplementary path SP, not on the main path MP, a problem that a slab,which does not need to be scarfed, is unnecessarily cooled due tounnecessary waste of the main path MP is prevented. Further, selectivescarfing is feasible for the slab in need of being scarfed.

FIG. 4 is a layout diagram illustrating a moving path for receiving anouter slab in the continuous casting and rolling apparatus, and FIG. 5is a layout diagram illustrating a moving path for receiving an outerslab and performing scarfing in the continuous casting and rollingapparatus.

Based on FIGS. 4 and 5, the introducing device 52 of the continuouscasting device according to an exemplary embodiment is configured toreceive at least one of the inner slab IS produced in the continuouscasting device 10 or the outer slab OP delivered from outside tointroduce the same onto the main path MP.

That is, the introducing device 52 is not limited to providing the innerslab IS produced in the continuous casting device 10 to the rollingdevice 30 and rolling the same; the introducing device 52 is configuredto introduce the slabs produced outside, thereby preventing rollingcapacity of the rolling device 30 from being wasted. This may serve toincrease a production yield of a product produced by the rolling device30.

Further, in consideration of the rolling capacity of the rolling device30, a plurality of the continuous casting devices 10 may be connected toa single rolling device 30 to form the main path MP. In another aspect,a moving path of the slab connecting the main continuous casting device10 and the rolling device 30 is formed as the main path MP, and the slabproduced in another continuous casting device 10 is delivered to therolling device through the supplementary path SP.

When the outer slab OS needs to be scarfed, a moving path passing thescarfing device 70 may be configured. A moving path passing the reheater60 may be configured when additional heating is required.

FIG. 6 is a diagram illustrating an order of the continuous casting androlling method of the present invention. Based thereon, a continuouscasting and rolling method according to another exemplary embodimentinvolves a process of supplying an inner slab, involving cutting aninner slab produced in a continuous casting device 10 and supplying thesame to a tunnel furnace 40; a rolling process involving pressing downthe slab received from a main path MP of the slab moving through thetunnel furnace 40; and a subworking process performed between the innerslab supply process and the rolling process and involving separating theslab on the main path MP from an outlet side of the tunnel furnace 40when the rolling process stops and introducing the slab onto the mainpath MP from an inlet side of the tunnel furnace 40 when the rollingprocess resumes.

The subworking process may serve to prevent a problem of a reducedactual yield, which may be caused by a defect of the rolling device 30or a scrapped slab during an abnormal operation in which a rollingoperation such as a replacement of a transfer roll is impractical.

That is, the slab located in the tunnel furnace 40 or that produced bymolten steel remaining in the continuous casting device 10 is separatedfrom the main path MP of the outlet side of the tunnel furnace 40 to beintroduced onto the supplementary path SP during the abnormal operation.Alternatively, the slab on the supplementary path SP is introduced ontothe main path MP of the inlet side of the tunnel furnace 40, therebyincreasing a time for which the slab is positioned on a moving path.

By securing a bypass, on which the slab remains without entering therolling device 30, the slab can be prevented from being wasted by thescrap treatment due to insecurity of the path on which the slab remains.

Besides, the slab introduced onto the main path MP is limited to beintroduced onto the inlet side of the tunnel furnace 40, therebycompensating for a temperature of the slab lowered during its transferthrough the supplementary path SP by a temperature at which the rollingcan be performed.

The process of supplying an inner slab involves producing of the innerslab IS using molten steel in the continuous casting device 10, and therolling process involves pressing down the slab by the rolling device 30to produce as a rolling product.

As previously described, the subworking process involves producing thesupplementary path SP in addition to the main path, through which theinner slab IS is delivered to the continuous casting device 10 and therolling device 30 such that the problem that the slabs are disposedduring abnormal operations is prevented.

More specifically, the subworking process of the continuous casting androlling method according to another exemplary embodiment may include adrawing process involving separating the slab on the main path from theoutlet side of the tunnel furnace when the rolling process stops; and anintroducing process involving receiving the slab separated from the mainpath of the outlet side of the tunnel furnace and introducing the sameonto the main path of the inlet side of the tunnel furnace when therolling process resumes.

That is, the drawing process involving delivering the slab from the mainpath MP to the supplementary path SP, and the introducing processinvolving delivering the slab from the supplementary path SP to the mainpath MP, are suggested.

The drawing and introducing processes are performed while not allowinganother process to intervene therebetween such that an additionalprocess is not performed on the supplementary path SP, and thisfacilitates a configuration of the slab remaining on the path.

That is, the subworking process of the continuous casting and rollingmethod according to another exemplary embodiment includes theintroducing process subsequent to the drawing process so as to excludeintervention of another step therebetween, when the slab introduced ontothe main path maintains a temperature for rolling when the slabintroduced onto the main path maintains at least a temperature forrolling.

The subworking process is performed for a case in which a period of timefor the abnormal operation is short enough that a cooling amount can becompensated in the tunnel furnace 40 while the slab remains on thesupplementary path SP.

However, in the case of a prolonged period of the abnormal operation,the cooling amount of the slab remaining on the supplementary path SPincreases, thereby disabling to secure the rolling temperature. In thiscase, the slab is reheated between the introducing and drawingprocesses.

That is, the subworking process of the continuous casting and rollingmethod according to another exemplary embodiment may include a reheatingprocess performed before the introducing process and involving heatingthe slab introduced onto the main path MP during the subworking processon the supplementary path SP when the slab has a temperature below therolling temperature.

The reheating process may be performed in the reheater 60 provided onthe supplementary path SP.

In addition, the subworking process of the continuous casting androlling method according to another exemplary embodiment may include ascarfing process performed before the introducing process and involvingscarfing the slab separated from the main path MP of the outlet side ofthe tunnel furnace 40 on the supplementary path SP through which theslab piece is delivered to be introduced onto the main path MP of theinlet side of the tunnel furnace 40.

The scarfing process may be performed in the case of producing anexterior material of a vehicle or a product required to meet stringentsurface quality requirements.

To this end, the scarfing process is performed in a scarfing device 70provided on the supplementary path SP. This may prevent a problem of themain path MP elongated by the scarfing device 70 as well as a problem ofthe slab on the main path MP being cooled.

Further, the subworking process of the continuous casting and rollingmethod according to another exemplary embodiment may include a processof supplying an outer slab, performed before the introducing process andinvolving introducing the outer slab OS produced outside onto thesupplementary path SP through which the slab separated from the mainpath MP of the outlet side of the tunnel furnace 40 is delivered to beintroduced onto the main path MP of the inlet side of the tunnel furnace40.

That is, the subworking process is not limited to providing the innerslab IS during the inner slab supply process, and further includessupplying an outer slab OS introduced from outside.

The process of supplying an outer slab supply is further performed suchthat the problem of capacity of the rolling device 30 being wasted isprevented.

That is, the outer slab supply process of the continuous casting androlling method according to another exemplary embodiment is performedwhen capacity of the slab pressed during the rolling process is largerthan an amount of the inner slab IS being supplied.

While embodiments have been shown and described in detail above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentdisclosure as defined by the appended claims.

1. A continuous casting and rolling apparatus, comprising: a continuouscasting device; a cutting device disposed on an outlet side of thecontinuous casting device and cutting an inner slab produced in thecontinuous casting device; a rolling device pressing a slab down anddisposed downstream of the continuous casting device in a movingdirection of the inner slab; a tunnel furnace provided between thecutting device and the rolling device and heating a slab located on amain path of the inner slab transferred from the continuous castingdevice to the rolling device; and a loading adjustment unit providedadjacent to the tunnel furnace, separating the slab on the main pathfrom the tunnel furnace and introducing the slab onto the main path froman inlet side of the tunnel furnace.
 2. The continuous casting androlling apparatus of claim 1, wherein the loading adjustment unitcomprises: a drawing device provided adjacent to an outlet side of thetunnel furnace and separating the slab from the main path to beintroduced onto a supplementary path; and an introducing device providedadjacent to the inlet side of the tunnel furnace and receiving the slabthrough the supplementary path to be introduced onto the main path. 3.The continuous casting and rolling apparatus of claim 2, wherein theloading adjustment unit is configured to introduce the inner slab,separated from the main path of the outlet side of the tunnel furnace bythe drawing device, onto a main path of the inlet side of the tunnelfurnace by the introducing device.
 4. The continuous casting and rollingapparatus of claim 2, wherein the apparatus comprises a reheating deviceon the supplementary path between the introducing device and the drawingdevice and heating the slab on the supplementary path.
 5. The continuouscasting and rolling apparatus of claim 2, wherein the apparatuscomprises a scarfing device provided on the supplementary path betweenthe introducing device and the drawing device and heating the slab onthe supplementary path.
 6. The continuous casting and rolling apparatusof claim 2, wherein the introducing device is configured to receive atleast one of an inner slab produced in the continuous casting device andan outer slab transferred from the outside and introduce the same ontothe main path.
 7. A continuous casting and rolling method, comprising: aprocess of supplying an inner slab, involving cutting an inner slabproduced in a continuous casting device and supplying the same to atunnel furnace; a rolling process involving pressing down the slabreceived from a main path of the slab moving through the tunnel furnace;and a subworking process performed between the inner slab supply processand the rolling process and involving separating the slab on the mainpath from an outlet side of the tunnel furnace when the rolling processstops and introducing the slab onto the main path from an inlet side ofthe tunnel furnace when the rolling process resumes.
 8. The continuouscasting and rolling method of claim 7, wherein the subworking comprises:a drawing process involving separating the slab on the main path fromthe outlet side of the tunnel furnace when the rolling process stops;and an introducing process involving receiving the slab separated fromthe main path of the outlet side of the tunnel furnace and introducingthe same onto the main path of the inlet side of the tunnel furnace whenthe rolling process resumes.
 9. The continuous casting and rollingmethod of claim 8, wherein the subworking process involves theintroducing process subsequent to the drawing process so as to excludeintervention of another step therebetween, when the slab introduced ontothe main path maintains a temperature for rolling.
 10. The continuouscasting and rolling method of claim 8, wherein the subworking processfurther comprises reheating performed before the introducing process andinvolving heating the slab introduced onto the main path during thesubworking on the supplementary path when the slab has a temperaturebelow the temperature for rolling.
 11. The continuous casting androlling method of claim 8, wherein the subworking process furthercomprises a scarfing process performed before the introducing processand involving scarfing the slab separated from the main path of theoutlet side of the tunnel furnace on the supplementary path throughwhich the slab is delivered to be introduced onto the main path of theinlet side of the tunnel furnace.
 12. The continuous casting and rollingmethod of claim 8, wherein the subworking process further comprises aprocess of supplying an outer slab, performed before the introducingprocess and involving introducing the outer slab produced outside ontothe supplementary path through which the slab separated from the mainpath of the outlet side of the tunnel furnace is delivered to beintroduced onto the main path of the inlet side of the tunnel furnace.13. The continuous casting and rolling method of claim 12, wherein theprocess of supplying an outer slab is performed when capacity of theslab performing pressing down during the rolling process is larger thana supply amount of the inner slab.